Respiratory illness is a major killer worldwide, consistently featuring in the top 10 leading causes of death as per the World Health Organisation (WHO). The problem is worse in developing countries such as India, where respiratory illness as the 2nd largest killer. Ventilators are used to provide crucial, life-saving respiratory support in case of respiratory distress and failure. These are used not only for respiratory illness, but also in other medical scenarios, such as post-cardiac surgery and so on, to reduce respiratory effort and divert the patient's resources to other critical organs.
However conventional ventilators are very expensive, often-times invasive and require highly skilled staff to operate them. Ventilator support is thus short in supply, especially in poorer, developing countries, thereby depriving many, especially from the poorer sections of society, from receiving crucial life-saving respiratory support in medical emergencies.
Further, conventional ventilators are generally the positive-pressure types, which force air at higher than atmospheric pressures into the lungs. These ventilators are known to cause further medical complications and even death, for example, volutrauma and barotrauma due to high pressures, and infection and pneumonia due to the invasive and forceful nature of these devices. There is in fact a distinct class of medical injuries called “Ventilator Induced Lung Injury” (VILI).
As a result of these dangerous “side-effects” conventional positive-pressure ventilators are especially not suitable for new-born infants, especially premature infants, who often need initial respiratory support to survive. In preterm infants, the high pressures used in these devices cause broncho-pulmonary dysplasia or chronic lung disease of the newborn or cognitive impairment, causing severe disability for life. In fact, in infants less than 1 kg weight, they are considered to be “not cost-effective” and thus many a precious life is lost.
Negative pressure ventilators are also present in the prior art, in fact these were the first type of ventilators to be developed, and were the only types that were life-saving during the polio epidemic of the 1950s. The traditional types encase the entire body in a tank and reduce the pressure in tank, resulting in a negative pressure around lungs, which causes air to move via the nostrils into the lungs gently, at atmospheric pressure, to equalize the pressure. They thus mimic the natural breathing process, where movement of the respiratory muscles creates negative pressure in the lungs, and ambient air moves in through the nostrils to equalize the pressure.
Although highly effective, negative pressure ventilators still have several drawbacks. E.g. the neck seal can cause cerebral hemorrhage and neck soreness. Patient care also becomes difficult, as the entire body was enclosed in a tank. Also, since the entire body is enclosed in a negative pressure chamber, venous return to heart is impeded.
Cuirass type negative pressure ventilators, which enclose the chest and abdomen of the user, are an improvement which eliminates the above drawbacks of traditional negative pressure ventilators, but these also have a number of limitations. The cuirass is large, unwieldy, to fit differently sized users and are connected with long, large bore pipe to a large vacuum pump, which generates the required negative pressure in the cuirass. The vacuum pump needs to be large as there is a lot of dead space within the cuirass and the wide bore pipe, which has to be evacuated and also because it needs to quickly generate the required negative pressure. Due to this large size of the vacuum pump, the device consumes high power, is very noisy, heavy and expensive. It thus cannot be used in poorer areas, and in areas with low, unstable or no electric supply, such as rural villages.
Further, cuirass ventilators, though portable, are not ambulatory, due to the cumbersome wide bore pipe connected to the large and heavy vacuum pump.
e.g. People suffering from chronic respiratory illness such as asthma, or chronic bronchitis (which affect a large number of children and adults worldwide), need ventilator support in their daily lives, due to exhaustion of respiratory muscles. However, they are unable to move about freely, due to the attached tube and heavy vacuum pump, thereby severely restricting their activities, productivity and quality of life.
There is thus a grave need worldwide for a ventilator device that is ambulatory, safe, low-cost, low-power as well as easy-to-use while having all advanced functionality of conventional ventilators, like customizable settings for users, safety alarms, additional sensors, nebulization, humidification etc. and which can thus provide life-saving and life-enhancing respiratory support to people of all economic backgrounds, without disrupting their daily lives, in a safe manner.